Current modeling of the tear film acknowledges a larger presence and role of mucin in its structure and function. The objective of this application is to produce a tear supplement of natural, purified mucin, and establish its effects on the structure, stability and lubrication of the tear film, using the clinical model accepted by the FDA. No available products have shown any treatment effect versus control (saline). This would therefore be a medical advance over all currently available products. The specific aims of Phase II of the proposed research are: 1. Validate the process for recovering milk mucin from acid dairy whey. 2. Continue characterization of the milk mucin from acid dairy whey, particularly with regard to any lipid complexing. 3. Perform the required preclinical testing and submit an investigational new drug (IND) application to the FDA. 4. Finalize the milk mucin based dry eye solution, guided by objective in- vivo tear film interferometry and clinical examination, as well as subjective grading of symptoms and comfort. 5. Assess the milk mucin based dry eye solution on eye to demonstrate proof of concept and establish clinical significance. 6. Prepare a business plan to present to potential partners and/or investors. PROPOSED COMMERCIAL APPLICATION: Our product would be an improvement over current commercial products in virtually all cases of dry eye. An FDA approved product that actually treats dry eye or relieves symptoms beyond that of placebo would increase the dollar value of the approximately $100 million dry eye market by opening up a non-OTC, therapeutic market that currently does not exist for dry eye.